If you lost enough coolant to make your heater blow cold, I would pull the egr valve and look at the condition of your intake manifold. If it is wet, you probably have a bad egr cooler. It should be dry and kind of ashy. I had that problem and my intake manifold had coolant in it. Did an egr delete and all problems seem to be solved.

 

Well just got home. Drove 70 all the way home. Released any pressure before I left work. Heater tried to blow cold at one stop but went back to normal when I started moving and stayed fine after that. Temps stayed perfect all the way 200 ect 206 eot although it did seem like the eot took longer to get up then normal. Got home and hoses were tight. I released the pressure and coolant was still about normal. It did appear to puke a tad on the top only and the cap was pressurized normally. This is an interesting one.

2006 F350 4X4

 

read this for the no heat...https://www.ford-trucks.com/forums/1364567-no-heat.html

I think your overly worried, seems your waiting until the truck blows up to say... I knew it, relax.

 

Thanks. I'll take a look when I get back to the house. Haha--I'm actually extremely comfortable with the motor and it hasn't given any reason to doubt it yet. Just the one or two "anomalies" I've had. With this current thing other then having to clean the mess is my analytical mind working on how the heck you can have an intermittent cooling issue. Since I know it wasn't over filled but that is exactly what it has acted like. It's the figuring out part I'm more concerned with then the problem itself (other then hg cause I don't want to do them---$$$) 😆

2006 F350 4X4

 

Check water pump flow, maybe the impellar bit the dust

 

My mind had thought about that. Although it's not warm out the fact it wasn't overheating had me on the fence about it. I would say if the pump is toast and didn't overheat that makes these engines even more awesome then I thought before (60 miles today at 60 to 75mph)

2006 F350 4X4

 

you said the heater hoses were hard, I'm thinking it's a blend door thingy.

 

I did think about the blend door as a possible issue. Could a backup in that part of the system cause puke? It definitely is on my list.

2006 F350 4X4

 

Naa,There is nothing to stop it up like that.What kind of heater controls do you have?

 

The push button auto type. The thread that Watson posted is a good one. I can run the self test and seems to be easy fixes. I would think that whatever the issue they should be connected as they started at the SAME time--this is what has me stumped ie: bad degas cap--I would understand . Bad blend door, actuator or blend door yep makes sense. Lower ect this morning doesn't fit unless I have no coolant but I do and it was fine on the way home. So I don't understand the factor tying all three together.

2006 F350 4X4

 

During the recent cold snap... my mishi 200 when I stop at lights cools down to 196-198 all the time. Get going, back to 200-204 and my EOT doesn't move as fast, stays around 204 all the time and it's slower to cool because it's thick. I think you may have a blend door issue. The puking may be something all together different. Puking coolant is a pressure thing as in head gasket thing, add a gauge to the line to be sure of how much pressure.

Lastly, not long after I changed my stat, mine puked to the bottom of the degas bottle. Filled it to min line and been steady since.

 

I got a feeling you got the same problem I have. I haven't done the tests yet but I think my EGR cooler is slightly cracked and lets in gases when it gets really cold forming a gas pocket in the system.......I just ordered a IPR EGR delete kit and a oil cooler plus some other goodies. I doubt it's the head gaskets but we shall see after the delete is in

 

Yep def. a pressure thing on the puke. Had my stat in since November so don't think that was it. Will def. have to put a gauge on it.

That is my best hope as I'm working on getting the delete stuff now--working on the funds. We'll get em figured.

2006 F350 4X4

 

are you heater core hoses about the same temp? after the truck is warmed up feel each hose going to the heater core. I had my heater core block up and it acted a lot like yours. come to a stop and cold air. start moving and heat comes back. eventually I lost all heat and had to replace the heater core.

 

I thought you just did work to your truckwhat did you do and was it doing this before I assume NO